ARM64: Access has_pending_message_ correctly.

src/arm64/full-codegen-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
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@@ skipping 4802 matching lines @@
   __ Push(result_register(), x10);
 
   // Store pending message while executing finally block.
   ExternalReference pending_message_obj =
       ExternalReference::address_of_pending_message_obj(isolate());
   __ Mov(x10, pending_message_obj);
   __ Ldr(x10, MemOperand(x10));
 
   ExternalReference has_pending_message =
       ExternalReference::address_of_has_pending_message(isolate());
+  STATIC_ASSERT(sizeof(bool) == 1);   // NOLINT(runtime/sizeof)
   __ Mov(x11, has_pending_message);
-  __ Ldr(x11, MemOperand(x11));
+  __ Ldrb(x11, MemOperand(x11));
   __ SmiTag(x11);
 
   __ Push(x10, x11);
 
   ExternalReference pending_message_script =
       ExternalReference::address_of_pending_message_script(isolate());
   __ Mov(x10, pending_message_script);
   __ Ldr(x10, MemOperand(x10));
   __ Push(x10);
 }
 
 
 void FullCodeGenerator::ExitFinallyBlock() {
   ASM_LOCATION("FullCodeGenerator::ExitFinallyBlock");
   ASSERT(!result_register().is(x10));
 
   // Restore pending message from stack.
   __ Pop(x10, x11, x12);
   ExternalReference pending_message_script =
       ExternalReference::address_of_pending_message_script(isolate());
   __ Mov(x13, pending_message_script);
   __ Str(x10, MemOperand(x13));
 
   __ SmiUntag(x11);
   ExternalReference has_pending_message =
       ExternalReference::address_of_has_pending_message(isolate());
   __ Mov(x13, has_pending_message);
-  __ Str(x11, MemOperand(x13));
+  STATIC_ASSERT(sizeof(bool) == 1);   // NOLINT(runtime/sizeof)

[jbramley, 2014/04/09 13:41:12]

This is defined in the ABI for both ARM and AArch64. It's also true for the
simulator host environments I tested (gcc 4.8.1 on Ubuntu 13.10). If it causes
trouble, we'll have to review how we handle accesses to fields where the size is
determined by the host environment. We might need templated Ldr/Str variants to
load host data types, for example.

[ulan, 2014/04/09 13:51:47]

Another solution would be to change the type of "has_pending_message" to
something platform-independent, like int8_t or int32_t. Jochen, wdyt?

+  __ Strb(x11, MemOperand(x13));
 
   ExternalReference pending_message_obj =
       ExternalReference::address_of_pending_message_obj(isolate());
   __ Mov(x13, pending_message_obj);
   __ Str(x12, MemOperand(x13));
 
   // Restore result register and cooked return address from the stack.
   __ Pop(x10, result_register());
 
   // Uncook the return address (see EnterFinallyBlock).
@@ skipping 128 matching lines @@
   return previous_;
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64